Study is directed toward increasing the service life of amalgam restorations. The most common cause of failure is embrittlement associated with galvanic corrosion of the Sn-Hg gamma-2 alloy phase. Laboratory corrosion cells with graphite anode and aqueous sulfide- chloride electrolyte simulate the oral corrosion process. This is used as screening test to evaluate alloy and clinical modifications. Laboratory prepared spherical alloys containing copper as minor alloying element permit generation of refined microstructures. Reduced interconnection of the gamma-2 phase reduces corrosion rate by limiting accessibility. Heat treat modifications favor formation of dense, coherent, protective alloy layers. Plating treatments are under development to permit amalgam patching of a chipped, but otherwise serviceable restoration, to original contour.